Synonyms and other taxonomic changes
used to be treated as a suborder of Neuroptera
Numbers
~260 extant spp. total, in two families: Raphidiidae, with 2 genera (
Agulla and
Alena) and 18 spp. in our area; and Inocelliidae, with 3 spp. of (
Negha) in our area
(1)Identification
Snakefly larvae can be confused with campodeiform beetle larvae but lack the terminal appendages
Raphidiid larvae have 7 simple eyes on each side vs 4 (incl. 2 minute ones) in Inocelliidae (Carpenter 1936)
pupa
Adults are similar to
Neuroptera but with elongate
prothorax.
Females can be easily distinguished by the presence of long tail-like
ovipositor (not a stinger!)
♀
♂
the two families can be distinguished as follows:
(2)
ocelli present; forewing with pterostigma bisected by a veinlet =>Raphidiidae
ocelli absent; forewing pterostigma not bisected =>Inocelliidae
Shape of the head can be fairly useful. Inocelliidae have parallel-sided rectangular heads vs more kite-shaped in Raphidiidae:
Inocelliidae
Raphidiidae
However, head shape vary somewhat in Raphidiidae.
Range
In our area, western, with most spp. west of the Rockies
Habitat
All sorts of arboreal/shrub habitats (in northern temperate zone from sea level to timberline.) Inocelliidae and a part of the Raphidiidae probably develop under bark. The majority of Raphidiidae have larvae that live in superficial layers of soil, particularly in the detritus around the roots of shrubs, sometimes in rock crevices. (Aspöck 2002)
Food
Both larvae and adults are predatory, though they are capable of catching and killing only small and weak prey. Snakefly larvae feed on eggs and larvae of various insects, as well as adults of minute arthropods (e.g. mites, springtails, barklice, and homopterans). Adults typically prefer aphids but may eat a wide variety of arthropods. Adults of at least some species can also feed on sugary substances. They take the effort to clean themselves after feeding. Females have been observed to frequently wag the ovipositor while eating. (Carpenter 1936:104)
Life Cycle
adapted from Aspöck (2002):
The egg stage lasts from a few days up to 3 weeks.
The larval phase lasts at least a year, 2-3 yrs in most species (under experimental conditions, some individuals up to 6 yrs). The number of larval instars not fixed, it varies around 10–11, but may reach 15 or more. The prepupal stage lasts a few days.
Pupation (usually) in spring, lasts from a few days up to ~3 weeks. A period of low temperature (around 0°C) is needed to induce pupation or emergence of the adult.
Remarks
Snakefly larvae have the unusual ability to scurry rapidly both forward and backwards
(3) --
video
Although adult females appear to have a long "stinger" (actually an ovipositor), snakeflies do
not sting and are considered medically
harmless to humans. In fact, they are thought to be beneficial as predators of forest pests. However, like all predatory insects, they are capable of biting if threatened.
(3)
"The Mesozoic biodiversity of the Raphidioptera was indeed much richer" (Aspöck 2002)
Print References
Aspöck H. (1986) The Raphidioptera of the World: A review of the present knowledge. Recent Research in Neuroptology: pp 15–29. (
Full Text)
Aspöck H., Aspöck U., Rausch H. (1991) Die Raphidiopteren der Erde. Goecke & Evers, Krefeld. Vol. 1, 730 pp. Vol. 2, 550 pp.
Aspöck H. (1998) Distribution and biogeography of the order Raphidioptera: updated facts and a new hypothesis. Acta Zool. Fenn. 209: 33–44.
Aspöck H. (2002) The biology of Raphidioptera: A review of present knowledge. Acta Zool. Acad. Sci. Hungaricae 48 (Suppl. 2): 35–50
(Full text)
Aspöck U. (1974) Die Raphidiopteren der Nearktis (Insecta, Neuropteroidea). Dissertation. Univ. Wien 1974: 1-238.
Aspöck, U. (1975) The present state of knowledge on the Raphidioptera of America (Insecta: Neuropteroidea). Polskie Pismo ent. (Bull. ent. Pol.) 45: 537–546. (
Full Text)
Carpenter F.M. (1936) Revision of the Nearctic Raphidiodea (Recent and fossil). Proc. Amer. Acad. Arts & Sci. 71: 89-157. (
Full Text)
